1. Field of the Invention
The invention pertains to vehicle seat supports permitting adjustment in forward and rear directions wherein the seat may be locked in a predetermined position.
2. Description of the Related Art
Industrial and agricultural vehicles such as lift trucks, tractors, garden tractors, mowers, and the like, include a seat for the operator that is often pivotally mounted to the vehicle adjacent the seat front end whereby the seat may be pivoted in a partially inverted relationship, usually for the purpose of protecting the seat from weather conditions. Further, such vehicle seats are sometimes adjustable in forward and rearward directions to provide maximum comfort for the operator to accommodate longer and shorter limbs. Forward and rearward seat adjustment movement is often accomplished through track and guide arrangements existing between components mounted upon the vehicle, and those affixed to the vehicle seat.
In known vehicle seat constructions of this type, assembly of the vehicle mounted portions of the seat structure with the seat mounted portions often are difficult to accomplish because of clearance and access limitations. Also, the assembly of the seat to its vehicle mounted structure is often difficult and care must be taken to insure that the assembly is proper so that limited movement of the seat adjustment is maintained for safety purposes.
Additionally, vehicles seats of the above type capable of forward and rearward adjustment usually utilize relatively expensive components to achieve adjustment difficult to manufacture and assemble.
It is an object of the invention to provide a vehicle seat platform support which is of economical construction, permits forward and rearward adjustment of the seat, and permits the seat to be easily assembled to its platform in a locked condition between its operable limits of adjustment.
Another object of the invention is to provide a seat platform for vehicles which permits the platform to be pivotally mounted adjacent its forward region, and yet permits the seat to be adjusted in forward and rearward directions between limits, and a detent is employed to lock the position of the seat supporting platform at a location intermediate its maximum limits of adjustment.
Yet a further object of the invention is to provide an adjustable seat platform for vehicles capable of adjustable movement in forward and rearward directions wherein the components are of low cost but of high strength, and wherein those components directly associated with the seat may be easily mounted upon the vehicle supported components which will automatically be locked upon the vehicle component upon assembly therewith.
Preferably, the seat structure platform described below is mounted for pivotal movement at its front edge so that the vehicle seat may be tilted forwardly to a partially inverted orientation to protect the seat from weather conditions or for access purposes. However, it will be appreciated that the seat platform of the invention may be directly mounted on the vehicle in a non-pivotal manner.
The primary component of the adjustable seat platform is a flat base plate formed of stamped steel having front and rear ends, a central region between the front and rear ends, upper and lower sides and parallel lateral edges extending between the front and rear ends. The base plate is preferably formed by a stamping operation of steel, and the lateral edges are formed as flanges including a riser extending above the central region, and the riser terminates in lips which extend away from the base plate central region and each have a linear edge, the lips of the base plate are parallel and form guides or ways.
The base plate central region is lanced to provide an upstanding detent shoulder which functions as a stop, and a plurality of spaced detent shoulders, which may be defined by holes, are formed in one of the lateral edge risers intermediate the base plate front and rear ends.
A pair of tabs lanced from the central region extend downwardly from the base plate at the lateral edges adjacent the front end, and these tabs may be pivotally connected to a pivot bracket mounted upon the vehicle by pivot pins wherein the base plate is capable of pivotal movement adjacent its front end.
The vehicle seat, not shown in the drawings for purposes of clarity, is mounted upon a seat mount plate of flat configuration which also includes front and rear ends, a central region, upper and lower sides and lateral edges. The lateral edges of the seat mount plate are parallel to each other, and are, preferably, formed in a downward manner and shaped to define U-shaped tracks adapted to extend over the base plate lips. Preferably, a non-metallic bearing material, preferably of a thermoplastic nature, is mounted upon the base plate lips and is located between the base plate lips and the seat mount plate tracks whereby the seat mount plate will be movable upon the base plate in forward and rear directions in a smooth, relatively noiseless manner.
The seat mount plate includes a spring engageable shoulder lanced from the seat mount plate central region extending from the lower side thereof forming a shoulder stop surface spaced from and parallel to the seat mount plate rear end. A leaf spring affixed to the base plate adjacent the base plate rear end includes a free front end extending above the base plate upper surface an extent higher than the vertical dimension of the base plate risers wherein, upon inserting the seat mount plate tracks upon the base plate lips at the rear end of the base plate, movement of the seat mount plate toward the base plate front end will cause the spring engageable shoulder of the seat mount plate to engage and depress the leaf spring permitting the shoulder to ride over the leaf spring to assemble the seat mount plate to the base plate as desired. Once the leaf spring passes the spring engageable shoulder, the leaf spring will move upwardly into an abutting relationship with the shoulder to limit rearward movement of the seat mount plate on the base plate.
Also, the spring engageable shoulder extends downwardly toward the base plate upper surface sufficiently to permit engagement of the shoulder with the base plate stop abutment, which will limit forward movement of the seat mount plate on the base plate. Of course, the spring engageable shoulder and the stop abutment will be spaced sufficiently from the rear edge of the seat mount plate and the front edge of the base plate, respectively, to permit a liberal extent of forward and rearward movement of the seat mount plate on the base plate to adjust the seat location for a particular operator, yet maintain sufficient engagement between the seat mount plate and the base plate to adequately support the seat mount plate and vehicle seat for safety purposes.
Adjustment of the seat mount plate intermediate its maximum forward and rearward positions is achieved by a detent lever pivotally mounted to the underside of the seat mount plate. The detent lever includes a handle portion extending beyond the front end of the seat mount plate as to be accessible to the operator, and the lever also includes a detent selectively engageable with a detent shoulder defined upon the base plate lateral edge riser. An extension spring biases the detent lever in a direction tending to engage the detent with a detent shoulder.
Because the seat mount plate may be easily mounted to the underside of the seat structure, and because the seat mount plate may be easily assembled to the base plate merely by sliding the seat mount plate over the rear end of the base plate, the adjustable seat platform of the invention permits the seat structure to be readily mounted upon the vehicle, the stop structure provides important safety features as it limits movement of the seat mount plate on the base plate, and the stamped configuration of the components permits the components to be manufactured at a relatively low cost.